I have this same problem with my R129.
I pulled the cluster out to replace a bulb and cracked the lens.
So I had to disconnect the harnesses to remove the cluster out for the lens replacement.
When I put everything back together, the SRS light became an issue just like OneBadViper...light stays on after system diagnostics, and stays on for a couple of minutes.
I had hoped someone would have an answer to this one...do seat belt switches fail as a result of replacing burnt out cluster bulbs?
